TaskAgent is a simple to-do list manager that saves its lists as plain text files. While Dropbox syncing is optional, the benefit is that you can edit your lists from outside the app using your favorite text editor and then sync any changes back into the app.

TaskAgent features:
-Interactive list interface: simple and easy to use
-Powered by plain text files: view and edit your lists even from outside the app
-Dropbox sync: your lists will always be there for you
-All tasks can be assigned an optional note
-Hotkey for quick task input
-Support for multiple lists
-List archiving option
-Task sorting options
-Quickly search all tasks
-iOS version of the app is available as a separate purchase

*Please note that TaskAgent only supports text files that are formatted as UTF-8 and uses a specialized app folder for Dropbox syncing.*